Laravel Testing for OTP failed after 30 minutes

I am writing a test case for checking whether otp is entered after 30 minutes.

Controller:

public function verifyOTP(VerifyOTPRequest $request)
    {
        $user = User::where([
            ['username', '=', $request->username],
            ['otp', '=', $request->otp]
        ])->first();
        $now = Carbon::now();
        if (!$user) {
            return response()->json([
                'success' => 'error',
                'message' => 'Your OTP is not correct'
            ], 503);
        } elseif ($user && $now->isAfter($user->otp_expiry_time)) {
            return response()->json([
                'success' => 'error',
                'message' => 'Your OTP has been expired'
            ], 503);
        }
        auth()->login($user, true);
        $user->update([
            'otp' => null,
            'otp_expiry_time' => null,
        ]);
        $accessToken = auth()->user()->createToken('authToken')->plainTextToken;
        return response()->json([
            'success' => 'success',
            'message' => 'Login Successfully',
            'access_token' => $accessToken
        ], 200);
    }

Testing:

public function test_late_otp_for_login(): void
    {
        $user = User::factory()->create();
        $this->postJson('/api/v1/login', [
            'username' => $user->username,
            'password' => 'password',
        ]);
        $knownDate = Carbon::create(2023, 7, 22, 19);
        Carbon::setTestNow($knownDate);
        $user = User::where('id', $user->id)->first();
        $response = $this->postJson('/api/v1/verify_otp', [
            'username' => $user->username,
            'otp' => $user->otp,
        ]);

        $response->assertStatus(503);
        $response->assertJsonFragment([
            "success" => "error",
            'message' => 'Your OTP has been expired',
        ]);
    }

Even if i set carbon it set time it is not working. Please help me